The rust holes in these sail panels are challenging to repair. There isn’t sufficient room to get a dolly behind them, to allow hammering on-dolly, which is the most straightforward way to control the shrinking and distortion caused by welding. In situations like this, there are other strategies that can be helpful.
Q.
It was great to meet you at your recent workshop in Pennsylvania. When I came home, I got my TIG machine fired up and practiced a bit, not expecting to get a job that required it so quickly. I have a remote control that clips onto the torch, which has a thumbwheel that takes the place of the foot pedal, but I have a bit of a problem coordinating my thumb motion while trying to hold the torch steady, so I prefer to use the foot pedal.
I’ve enclosed some pictures of my current job, the back window recess of a 1967 Pontiac GTO. As you can see, it is rusted out on both sides. The damage is in a spot that’s tough to reach, even with the trunk lid off.
The body is off the frame, and I’ve placed it on a homebuilt stand, so I have to stand on a platform to reach the damaged areas. My customer is as picky as they come, and I’m OK with that, I just don’t want to mess the job up.
There is no room to get a dolly behind the rusted areas, so it’s nearly impossible to hammer on the welds, and I would hate to have the panel warp. Should I just weld a little, then stop and let things cool. The required patches are small, and as far as my customer is concerned. Time isn’t a big deal.
On another subject, I bought some Wiss metal shears like you recommended in class, and all I can say is you have to have strong wrists. You make it look easy.
Thanks,
Tom McBride
Via the Internet
A.
First, about the shears. My 72-year old hands really aren’t that strong. If you are having trouble cutting steel up to 18-gauge thickness, try rotating the shears a tiny bit as you are cutting. The motion is in your wrist, like you do when opening a door with a doorknob. Just a tiny bit of rotation can make a big difference in the cutting force required. There is sort of a “sweet spot” you will find with a little experimentation. With the red-handled shears, you would twist the handles clockwise, and you would twist counterclockwise with the green-handled shears.
I have both hand and foot controls for my TIG welders, and I prefer the foot pedal too. This is a matter of personal preference, and some welders use the thumb control for just about every job they do. There are some situations where the thumb control is a great asset (like if you are standing on a ladder) but I only use it on rare occasions.
Now, about the rust damage you need to repair. Yes, I see that the welds will be in a difficult area, but you really don’t have a lot of options. Get the best fit-up you can, and keep the heat down as much as possible when welding. If you make little 1/4-inch welds, skip around, and let the metal cool completely each time, you will build up much less heat than if you weld long sections.
After welding, you can tap any high spots down, but you’ll be limited to prying any low spots up if you can’t get a dolly behind them.
If your TIG machine has pulse capabilities (usually only high-end machines do) the pulse settings can be used to reduce the heat input, which will reduce the shrinking and warping, too. You could also use silicon bronze filler rod, which has plenty of strength for small patches like you’ll need, and it causes much less distortion than steel rod.
Good luck to you, and let me know if you have any additional questions.
You can email your questions to Professor Hammer: covell@cruzio.com or send a letter to: Covell Creative Metalworking, 106 Airport Blvd., Suite 105, Freedom, CA 95019; you’ll receive a personal reply! Ron Covell has made many videos on metalworking, and they can now be streamed or downloaded from his website! Check these out at covell.biz, along with his ongoing series of workshops across the nation, or call for a current schedule of workshops and a free catalog of DVDs. Phone (800) 747-4631, or (831) 768-0705. You’ll also enjoy Ron’s YouTube channel; www.youtube.com/user/covellron.
The post Repairing rust damage in restricted areas appeared first on Hot Rod Network.